The bill would have made it possible for any "employer, health plan provider, health plan sponsor, health care provider, or any other person or entity" to refuse to provide coverage for contraception, abortion, or sterilization.

"For the first time, this bill would allow insurance companies to impose their will, and deny contraceptive coverage to women - even if women and their employers want it included," said Nixon in a statement on his decision. "We want families making these decisions - not insurance companies. For that reason, I am vetoing this bill."

The bill brought together an interesting group of opponents, linking pro-choice and reproductive rights groups with labor unions like AFL-CIO, who were disturbed by the impact on employees' access to birth control. Catholic and pro-life groups were the most vocal proponents of the bill, calling it a "religious freedom" bill. Read the full language here.

Nixon's decision comes after a suspenseful waiting period following the bill's passage in the legislature. The governor has a mixed record on abortion and reproductive issues, and many wondered if he would simply allow SB 749 to pass by neither signing nor vetoing it, as he has done with past abortion bills.

Both Planned Parenthood and the ACLU of Eastern Missouri applauded today's decision.

"SB 749 would have put health insurers in the difficult position of having to obey an unconstitutional state law at the expense of women's reproductive rights," wrote the ACLU's Brenda Jones. "Gov. Nixon's action today spared the state from what would have been an expensive and disruptive mandate."

"We encourage Missouri legislators to override Governor Nixon's veto during the veto session in September," read their statement. "We encourage Catholics and people of all faith to continue to pray for religious liberty in our state and in our nation."

Watch Nixon explain his reasoning on SB 749:

Here are the Governor's full remarks:

Among other bills, I am vetoing Senate Bill 749. As a person of faith, I cherish the freedom we all have to worship in accordance with our own beliefs. Our churches should be free from the encroachment of government and politics.

For more than a decade, Missouri law has provided strong religious and moral protections to safeguard the beliefs of employees and employers regarding contraceptive coverage. Those protections apply whether the employer is a church or religious organization, or not. Either way, religious and moral beliefs are protected.

These protections are strong. They're effective. And they have my support.

Under our existing law, employees and employers can already opt out of providing or receiving contraceptive coverage if doing so conflicts with their religious or moral convictions.

At the same time, our existing law also acknowledges the rights of women and families who want to access contraception.

For employees whose companies have chosen to invoke our religious or moral protections, current law also ensures that women and families who want contraceptive coverage can get it - a right that I also support.

Our existing law protects religious liberties - and it respects individual rights. The current law was passed overwhelmingly. It's been on the books for years. And it works.

The additional provisions included in Senate Bill 749 - such as the notice requirement for individual policies - are worthwhile ideas that deserve continued discussion.

For the first time, this bill would allow insurance companies to impose their will, and deny contraceptive coverage to women - even if women and their employers want it included.

This bill would allow insurance companies to override the rights and beliefs of employees and employers.

By doing so, the bill would shift authority to make decisions about access to contraceptive coverage away from Missouri women, families and employers - and put that power in the hands of insurance companies. That would be a step backward for Missouri.

This could also set a dangerous precedent for the future and other types of health care services, such as end-of-life care or cancer screenings.

We want families making these decisions - not insurance companies. For that reason, I am vetoing this bill.

Again, Missouri law already provides strong religious and moral protections. Missouri law also respects the rights of women and families to access contraception. And insurance companies should not have the power to overrule that right.

If the legislature were to pass a bill that includes the additional notice requirement for insurance policies, without limiting access to contraception or shifting authority to insurance companies, I would give that bill serious consideration.

And I'm certainly open to discussions about what that bill would need to look like.